tn-fd-22: client sata ssd smart attribute reference

Technical NoteClient SATA SSD SMART Attribute Reference

IntroductionThis technical note describes the self-monitoring, analysis, and reporting technology(SMART) feature set available for Micron's client SSDs. The SMART attributes are usedto protect user data and minimize the likelihood of unscheduled system downtime thatmay be caused by predictable degradation and/or fault of the device.

This document describes the SMART parameters available on the following client SSDproducts:

• M500 (MU03 firmware and later)• M510• M550• MX100• M600• MX200• 1100• MX300• 1300

TN-FD-22: Client SATA SSD SMART Attribute ReferenceIntroduction

CCMTD-1725822587-4940tnfd22_client_sata_ssd_smart_attributes.pdf - Rev. E 9/18 EN 1 Micron Technology, Inc. reserves the right to change products or specifications without notice.

© 2013 Micron Technology, Inc. All rights reserved.

Products and specifications discussed herein are for evaluation and reference purposes only and are subject to change byMicron without notice. Products are only warranted by Micron to meet Micron's production data sheet specifications. All

information discussed herein is provided on an "as is" basis, without warranties of any kind.

SMART Attribute Definitions

Table 1: SMART Attribute Definitions

ID (Dec) ID (Hex) Description

1 01h Raw read error rate

5 05h Reallocated NAND block count

9 09h Power-on hours count

12 0Ch Power cycle count

171 ABh Program fail count

172 ACh Erase fail count

173 ADh Average block erase count

174 AEh Unexpected power-loss count

180 B4h Unused reserve (spare) NAND blocks

183 B7h SATA interface downshift

184 B8h Error correction count

187 BBh Reported uncorrectable errors

194 C2h Drive temperature

196 C4h Reallocation event count

197 C5h Current pending ECC count

198 C6h SMART offline scan uncorrectable error count

199 C7h Ultra-DMA CRC error count

202 CAh Percent lifetime remaining

206 CEh Write error rate

210 D2h Successful RAIN recovery count

246 F6h Cumulative host sectors written

247 F7h Number of NAND pages of data written by the host

248 F8h Number of NAND pages written by the FTL

TN-FD-22: Client SATA SSD SMART Attribute ReferenceSMART Attribute Definitions



SMART Attribute Threshold DescriptionThe SMART attributes that use non-zero threshold values in some of Micron's clientSSDs are described in this section.

Table 2: SMART Attribute ID 5: Reallocated NAND Block Count

Applicable Products Applicable Firmware Revisions Threshold1 Advisory/Warranty

M600 MU02 and later 0Ah Advisory

MX200 MU02 and later 0Ah Advisory

1100 All 0Ah Advisory

MX300 All 0Ah Advisory

1300 All 0Ah Advisory

Note: 1. A threshold trip can occur when the SSD is approaching design tolerances for realloca-tion events. If reallocation event tolerances are reached, the device may enter a read-only mode.

Table 3: SMART Attribute ID 202: Percent Lifetime Remaining

Applicable Products Applicable Firmware Revisions Threshold1 Advisory/Warranty

M600 MU02 and later 01h Advisory

MX200 MU02 and later 01h Advisory

1100 All 01h Advisory

MX300 All 01h Advisory

1300 All 01h Advisory

Note: 1. A threshold trip can occur when the SSD has reached the end of its designed media en-durance. The device may continue to function beyond this point, but data retentionspecifications may no longer apply.

TN-FD-22: Client SATA SSD SMART Attribute ReferenceSMART Attribute Threshold Description



SMART ID 1 (01h): Raw Read Error Rate

Current Value (8 bits)

This value is the total number of correctable and uncorrectable ECC error events divi-ded by the total host pages read over the life of the drive.

VC = 100 - 100EC + EU

HP

Where:EC = Total number of correctable errorsEU = Total number of uncorrectable errorsHP = Total number of NAND pages read by the host

ECC errors occurring while reading non-user data will still contribute to this rate.

Worst Value (8 bits)

This field contains the lowest value of the Current Value field calculated over the life ofthe drive.

Raw Data (48 bits)

This data field holds the raw sum of correctable and uncorrectable ECC error eventsover the life of the drive. This value will saturate at FFFFFFFFh.

TN-FD-22: Client SATA SSD SMART Attribute ReferenceSMART ID 1 (01h): Raw Read Error Rate



SMART ID 5 (05h): Reallocated NAND Block Count


This value is calculated as:

VC = 100 100 - BRBT

Where:BR = Number of all retired blocksBT = The bad block threshold to enter WP mode



Raw Data (48 bits)

Represents the total number of reallocated NAND blocks due to grown bad blocks.

TN-FD-22: Client SATA SSD SMART Attribute ReferenceSMART ID 5 (05h): Reallocated NAND Block Count



SMART ID 9 (09h): Power-On Hours Count


This value is hard-coded to 100% (64h).



Raw Data (48 bits)

This value gives the raw number of hours that the drive has been under power (online)over its lifetime.

This attribute shall increment for each hour in the following link power state:

• SATA PHYRDY (Link Active)

This attribute may not increment for each hour in the following link power states:

• SATA Partial• SATA Slumber• SATA Device Sleep

TN-FD-22: Client SATA SSD SMART Attribute ReferenceSMART ID 9 (09h): Power-On Hours Count



SMART ID 12 (0Ch): Power Cycle Count





Raw Data (48 bits)

This value gives the raw number of power-cycle events experienced over the life of thedrive.

TN-FD-22: Client SATA SSD SMART Attribute ReferenceSMART ID 12 (0Ch): Power Cycle Count



SMART ID 171 (ABh): Program Fail Count



VC = 100 - 100FP

FP + BR

Where:FP = Total number of program failsBR = Number of reserved blocks remaining


This value is the lowest Current Value recorded over the life of the drive.

Raw Data (48 bits)

This value contains the raw number of program failure events over the life of the drive.

TN-FD-22: Client SATA SSD SMART Attribute ReferenceSMART ID 171 (ABh): Program Fail Count



SMART ID 172 (ACh): Erase Fail Count



VC = 100 - 100EF

EF + BR

Where:EF = Total number of erase failuresBR = Current number of reserved blocks


This value is the lowest Current Value recorded over the life of the drive.

Raw Data (48 bits)

This value contains the raw number of erase failure events over the lifetime of the de-vice.

TN-FD-22: Client SATA SSD SMART Attribute ReferenceSMART ID 172 (ACh): Erase Fail Count



SMART ID 173 (ADh): Average Block-Erase Count



VC = 100 - 100EAVG

BL

Where:VC = Current valueEAVG = Average erase countBL = Rated life of a block (the rated erase count for the NAND used)



Raw Data (48 bits)

This value is the average erase count of all super blocks. One super block is defined toinclude all the physical blocks with the same block number of all planes.

TN-FD-22: Client SATA SSD SMART Attribute ReferenceSMART ID 173 (ADh): Average Block-Erase Count



SMART ID 174 (AEh): Unexpected Power Loss Count





Raw Data (48 bits)

This value is the total number of times the device has been power-cycled unexpectedly.

Unexpected power loss can be avoided by preceding a power off with an ATA STBI(STANDBY IMMEDIATE) command, and allowing the SSD to properly complete thiscommand before removing power to the SSD.

TN-FD-22: Client SATA SSD SMART Attribute ReferenceSMART ID 174 (AEh): Unexpected Power Loss Count



SMART ID 180 (B4h): Unused Reserve (Spare) NAND Blocks

Current Value

This value is hard-coded to zero (00h).

Worst Value

This value is hard-coded to zero (00h).

Raw Data


URBC = BT - BG

Where:URBC = Total unused reserved block count.BT = Total number of spare blocks when the drive left the factory. The spare block countrepresents the number of grown bad blocks the drive can handle in the field before itenters write protect.BG = Total number of grown bad blocks.

TN-FD-22: Client SATA SSD SMART Attribute ReferenceSMART ID 180 (B4h): Unused Reserve (Spare) NAND Blocks



SMART ID 183 (B7h): SATA Interface Downshift





Raw Data (48 bits)

Represents the total number of host interface speed downshifts on the SATA link. Forexample, the SATA link shifts to a lower-generation speed (1.5 Gb/s or 3.0 Gb/s) thanwhat was previously negotiated (6 Gb/s).

TN-FD-22: Client SATA SSD SMART Attribute ReferenceSMART ID 183 (B7h): SATA Interface Downshift



SMART ID 184 (B8h): Error Correction Count



VC = 100 - ENR- ER2

Where:ENR = Number of nonrecoverable errorsER = Number of recoverable errors


This value contains the lowest value of the Current Value field over the life of the drive.

Raw Data (48 bits)

This value represents the total number of end-to-end correction events, specifically er-rors on the write/read data path:

VR ENR ER = +

TN-FD-22: Client SATA SSD SMART Attribute ReferenceSMART ID 184 (B8h): Error Correction Count



SMART ID 187 (BBh): Reported Uncorrectable Errors





Raw Data (48 bits)

This value represents the total number of UECC errors reported by the drive as a resultof host commands (for example, READ commands).

TN-FD-22: Client SATA SSD SMART Attribute ReferenceSMART ID 187 (BBh): Reported Uncorrectable Errors



SMART ID 194 (C2h): Drive Temperature



VC = 100 - TC

Where:TC = Current temperature in degrees Celsius



VW = 100 - TM

Where:TM = Maximum temperature recorded over lifetime in degrees Celsius

Raw Data (48 bits)

The value is defined as:

Bytes

5 4 3 2 1 0

MAX temperature MIN temperature Current temperature

TN-FD-22: Client SATA SSD SMART Attribute ReferenceSMART ID 194 (C2h): Drive Temperature



SMART ID 196 (C4h): Reallocation Event Count





Raw Data (48 bits)

This value represents the total number of grown bad blocks. This value is calculated as:

VR = BT - BF

Where:BT = Total number of bad blocks on the driveBF = Number of factory marked OTP bad blocks

TN-FD-22: Client SATA SSD SMART Attribute ReferenceSMART ID 196 (C4h): Reallocation Event Count



SMART ID 197 (C5h): Current Pending ECC Count





Raw Data (48 bits)

This value represents the total number of ECC events found as a result of host com-mands (for example, READ commands) or during background operations.

TN-FD-22: Client SATA SSD SMART Attribute ReferenceSMART ID 197 (C5h): Current Pending ECC Count



SMART ID 198 (C6h): SMART Offline Scan Uncorrectable Error Count





Raw Data (48 bits)

This value is the cumulative number of unrecoverable read errors (UECC) found in themost recent media scan triggered by a SMART EXECUTE OFF-LINE IMMEDIATE com-mand. At the beginning of each media scan, this value shall reset to zero. If no mediascan has been previously run, this field will be zero.

TN-FD-22: Client SATA SSD SMART Attribute ReferenceSMART ID 198 (C6h): SMART Offline Scan Uncorrectable Error

Count



SMART ID 199 (C7h): Ultra-DMA CRC Error Count





Raw Data (48 bits)

This value represents the total number of CRC errors the drive has detected on the SATAinterface over the life of the drive. A CRC error is generated when the CRC check fails ona SATA Transport Layer FIS.

TN-FD-22: Client SATA SSD SMART Attribute ReferenceSMART ID 199 (C7h): Ultra-DMA CRC Error Count



SMART ID 202 (CAh): Percent Lifetime Remaining


This value gives the threshold inverted value of the raw data value below. That is, if 30%of the lifetime has been used, this value will report 70%. A value of 0% indicates that100% of the expected lifetime has been used.

This value is defined as:

VC = MAX[100 - VR, 0]

Where:VR = Raw data value


This field contains the lowest value of the Current Value field over the life of the drive.

Raw Data (48 bits)

This value is defined as:

VR = 100 EAVG

BL

Where:EAVG = Average erase count of all blocks.BL = Erase count for which the part is rated (block life)

TN-FD-22: Client SATA SSD SMART Attribute ReferenceSMART ID 202 (CAh): Percent Lifetime Remaining



SMART ID 206 (CEh): Write Error Rate


Represents a ratio of the number of NAND program fails to the number of host sectorswritten. This value is defined as:

VC = 100FN

ST

Where:FN = Total number of NAND program failuresST = Total number of sectors written


This field is the lowest value of the Current Value field over the life of the drive.

Raw Data (48 bits)

This value is the NAND program fail count.

TN-FD-22: Client SATA SSD SMART Attribute ReferenceSMART ID 206 (CEh): Write Error Rate



SMART ID 210 (D2h): Successful RAIN Recovery Count

Current Value


Worst Value


Raw Data

This value is the total number of Physical NAND Pages successfully recovered by Mi-cron's redundant array of independent NAND (RAIN) technology and increments whenRAIN is successful on valid and invalid user data.

TN-FD-22: Client SATA SSD SMART Attribute ReferenceSMART ID 210 (D2h): Successful RAIN Recovery Count



SMART ID 246 (F6h): Cumulative Host Sectors Written

Current Value


Worst Value


Raw Data

This value gives the total number of host sectors (LBAs) written by the host over the lifeof the drive.

TN-FD-22: Client SATA SSD SMART Attribute ReferenceSMART ID 246 (F6h): Cumulative Host Sectors Written



SMART ID 247 (F7h): Host Program NAND Pages Count

Current Value

This value is always 100% (64h).

Worst Value


Raw Data

This value stores the cumulative host program NAND page count.

TN-FD-22: Client SATA SSD SMART Attribute ReferenceSMART ID 247 (F7h): Host Program NAND Pages Count



SMART ID 248 (F8h): FTL Program NAND Pages Count

Current Value


Worst Value


Raw Data

This value stores the cumulative FTL program page count. This attribute tracks thenumber of NAND pages programmed by the FTL which are in addition to operationsprogrammed by the host.

Write amplification factor can be calculated by:

WAF = (Attrib_247 + Attrib_248) Attrib_247

TN-FD-22: Client SATA SSD SMART Attribute ReferenceSMART ID 248 (F8h): FTL Program NAND Pages Count



MechanismA SMART attribute is retrieved by the host issuing the SMART READ DATA command. Inthe 512-bytes returned by the SMART READ DATA command, bytes 0–361 (169h) aremarked as vendor-specific in the ATA8-ACS2 and ACS3 specifications. These contain theSMART attribute data.

Table 4: SMART Attribute Table Layout

OffsetLength(Bytes) Description

0 2 SMART structure version (vendor-specific)

2 12 Attribute entry #1

2 + 12 12 Attribute entry #2

… …

2 + (29 * 12) 12 Attribute entry #30

Each attribute entry contains 12 bytes, comprised of the following fields: ID, Flag, Cur-rent Value, Worst Value, Raw Data, and Reserved. There is no requirement on the orderof the attributes in the table.

For each attribute, there is a corresponding threshold that is retrieved by the host issu-ing the SMART READ ATTRIBUTE THRESHOLDS command. In the 512-bytes data re-turned by the command, the host can compare the threshold with the current value ofeach attribute. If the current value is less than or equal to the threshold, the device is ina status that requires further attention from the system. This procedure is also called aSMART threshold trip.

The SMART RETURN STATUS command will compare the current value attributes withthe threshold and return a status that specifies the self test has either completed with-out error (C24Fh) or detected a threshold has been exceeded (2CF4h). The SMART RE-TURN STATUS command replaces the functionality of the READ THRESHOLD VALUEand WRITE WARRANTY FAILURE THRESHOLD commands, and provides backward-compatibility with existing SMART applications.

Table 5: SMART Attribute Threshold Table Layout

The order of the threshold entries matches those in SMART Attribute Table Layout.

OffsetLength(Bytes) Description

0 2 SMART structure version (vendor-specific)

2 12 Threshold entry #1

2 + 12 12 Threshold entry #2

… …

2 + (29 * 12) 12 Threshold entry #30

TN-FD-22: Client SATA SSD SMART Attribute ReferenceMechanism



Attribute Definition

Table 6: SMART Attribute Entry Format and Definition

OffsetLength(Bytes) Field Name Data Description

0 1 ID00h Invalid entry.01h–FFh valid entry.

1 2 Flag

Bit 0: Prefailure/advisory bit. Applicable only when the current value is less thanor equal to its threshold.0 = Advisory: the device has exceeded its intended design life; the failure is notcovered under the drive warranty.1 = Prefailure: warrantable, failure is expected in 24 hours and is covered in thedrive warranty.

Bit 1: Online collection bit.0 = Attribute is updated only during off-line activities1 = Attribute is updated during both online and off-line activities.

Bit 2: Performance bit.0 = Not a performance attribute.1 = Performance attribute.

Bit 3: Error Rate bit. Expected, non-fatal errors that are inherent in the device.0 = Not an error rate attribute.1 = Error rate attribute.

Bit 4: Even count bit.0 = Not an even count attribute.1 = Even count attribute.

Bit 5: Self-preserving bit. The attribute is collected and saved by the drive with-out host intervention.0 = Not a self-preserving attribute.1 = Self-preserving attribute.

Bit 6–15: Reserved.

3 1Currentvalue

Normalized (normally from the raw data) attribute value.Valid range 1–253 (FDh); initial value 00 (64h).Values of 0, FEh, and FFh are invalid.This value can be compared to the threshold set by the device.The device should collect enough data before updating the normalized value toensure statistical validity.

4 1 Worst valueWorst ever normalized value.Valid range 1–253 (FDh); initial value 100 (64h).Values of 0, FEh, and FFh are invalid.

5 6 Raw data Vendor and/or attribute-specific.

11 1 Reserved 00h




Threshold Entry Definition

Table 7: SMART Attribute Threshold Entry Format and Definition

OffsetLength(Bytes) Field Name Data Description

0 1 IDCorresponds to the ID field in the SMART Attribute Entry Format and Definitiontable.

1 1 Threshold

00h = Valid threshold value, always passing, as the current value will always belarger.

01h = Valid threshold value.

FDh = Maximum value.

FEh = Invalid threshold value.

FFh = Valid threshold value, always failing.

2 10 Reserved 00h

Notes: 1. For SMART attributes that do not use thresholds, the Threshold field is set to 00h to in-dicate an always-passing condition.

2. For SMART attributes that use thresholds, the thresholds are specified in the SMART At-tributes Using Non-Zero Threshold Values section.




Revision History

Rev. E – 9/18

• Added 1300 to list of applicable SSDs.• Changed enclosure temperature to drive temperature.• Updated Worst Value for IDs 1, 5, 173 and 202.• Updated Raw Data for IDs 210 and 246.

Rev. D – 9/16

• Added 1100 and MX300 to list of applicable SSDs.• Added descriptions for IDs 247 and 248.• Added SATA to document title.• Reformatted document for easier reference.

Rev. C – 12/14

• Added the MX200 SSD.• Added notes to SMART Attribute Threshold Entry Format and Definition table.• Added the SMART Attributes Using Non-Zero Threshold Values section.• Removed the Attribute Flags and Reserved/Threshold sections from each SMART ID

section.

Rev. B – 10/14

• Updated to include M500 (MU03 Firmware and Later), M510, M550, MX100, andM600 client SSDs with firmware versions beginning in "MU."

• Updates to SMART Attribute Definitions table.

Rev. A – 3/14

• Initial release

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Micron and the Micron logo are trademarks of Micron Technology, Inc.All other trademarks are the property of their respective owners.

TN-FD-22: Client SATA SSD SMART Attribute ReferenceRevision History



tn-fd-22: client sata ssd smart attribute reference

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